Abstract: The 42CrMo large-sized roller rim requires surface induction hardening to enhance the wear resistance and service life of the rim. In the case of limited quenching frequency of the equipment, this study investigated the effects of overall preheating and induction quenching cooling methods on the formation of roller cracks and the depth of the hardened layer by designing and optimizing inductors, preheating the roller as a whole before surface quenching, designing process parameters, and selecting different quenching media. Research has shown that after adopting optimized process schemes such as sensors and overall preheating, the depth of the quenched layer of the roller reaches 6.153mm without cracks, fully meeting the requirements of 42CrMo roller induction hardening technology. A roller medium frequency induction hardening process scheme has been successfully developed.